I use button shellac almost exclusively for my FP finishes. It contains wax and I do not de-wax it. This is the same type of shellac that was used to finish gymnasium and ballroom floors prior to the invention of poly-urethanes in the 1950's. If it can stand up to that type of use it is plenty tough for guitars.

Here is a link to a video from my blog of a presentation I did on my FP process s few years ago. In it I talk about the advantages/disadvantages of waxed and de-waxed shellacs.
http://howardguitars.blogspot.com/2015/ ... l-way.html

Thanks for the responses guys.
I can't wait to try it out.

One of the harder things about life is that we just plain flat out don't know what we don't know.

I've been at this for years and just accepted that blonde shellac flakes were the only thing out there.
Tried dewaxing button lac a few times without ANY SUCCESS and am happy to have a new trick up my sleeve.

Dave

I use button shellac almost exclusively for my FP finishes. It contains wax and I do not de-wax it. This is the same type of shellac that was used to finish gymnasium and ballroom floors prior to the invention of poly-urethanes in the 1950's. If it can stand up to that type of use it is plenty tough for guitars.

Here is a link to a video from my blog of a presentation I did on my FP process s few years ago. In it I talk about the advantages/disadvantages of waxed and de-waxed shellacs.
http://howardguitars.blogspot.com/2015/ ... l-way.html

Thanks for chiming in Brian. I'm really interested in the waxes effect on shellac. Leaving it in seems like it's gathered more advocates in recent years.
Do you see a big difference in durability when wax is left in?
Is it possible wax was left in for gym floors because they needed a ton of it and getting it out added to the cost?

The wax was left in for durability, but it's not just the wax increasing the durability. Button lac is polymerized some in the process that makes the buttons from the seedlac making it a better linked film chain than flaked or any other type of shellac. The wax allows the shellac to take more abuse and not wear away as fast but it's nemesis is water.....to further protect the shellac coating a paste wax is generally used and guess what most high quality furniture paste waxes are made from......yep the wax they take out when they de-wax shellac. Hmmmm. and when you apply this over a shellac finish that still has it's natural wax in it the two bond at a molecular level giving a bonded wear absorbing layer to protect the finish underneath.

Them old timers might not have known the science behind it but they new what worked.

How could something vulnerable to water be considered durable?

Or does the additional wax coat make it waterproof? But that doesn't make any sense if it's the same kind of wax that's in the shellac to begin with, and that's what makes it vulnerable in the first place...

I have a tall case clock made in England in the 1740's in my living room with its original FP finish intact...... Hows that for durable? was even shipped across the ocean when that was a real hard trip. Meanwhile lacquer finishes done less than 50 years ago are checking and flaking and peeling.

Whiled I cannot say for sure whether the shellac has the wax in it or not I suspect it does.

This is a great topic and very worthy of discussion.
I raised this question back in 2007 and was mostly shot down for daring to challenge one of the Luthier Truths about dewaxing shellac by letting it decant.
http://luthiersforum.com/forum/viewtopic.php?f=10102&t=14830
I have always been impressed with the finishes on old Martins, Lyon & Healys, and other instruments at the turn of the 20th century. Many of these instruments have led a hard life with lots of playing and then possibly stashed in an attic somewhere for many years. The finish that remains looks fantastic. By most accounts this finish is a shellac of some sort, possibly with additional gums added. I think it is a stretch to think that a busy shop like Lyon & Healy would wait for shellac wax to settle in solution and then discard 10-20% of the dissolved mixture in order to get wax-free shellac.
I think it is safe to say that most knowledge of lac and shellac has been lost with the advent of cellulose and other modern coatings. The old timers who worked with this stuff are long gone. Those of us who see the advantages of lac are now tasked with rediscovering how to work with it.
There really isn't a more perfect finishing material than lac for small production, IMO. Quick drying, low toxicity, no special equipment or spray rooms required, and the best repair-ability of any finish out there. Once the learning curve of application is mastered the actual time spent from start to finish is probably less than most other instrument finishes, with the possible exception of UV-cured poly. Upon inspection of the finish on the early guitars previously mentioned durability is not an issue. There is a missing link somewhere, however. I have yet to find a lac product that rivals this finish and I have tried every grade of lac and shellac from stick lac through super blonde.
Like most agricultural products, lac has undoubtedly undergone changes in cultivation and harvesting since the early days of the 20th century. It is entirely possible that the lac we have these days is not our great grandfathers' lac. It has certainly undergone changes in the way it is processed. From what I can gather there are a two ways of processing lac: solvent and heating. Again, my knowledge of lac processing is sketchy but I believe blonde shellacs are solvent extracted. Real button lac, which looks like melted blobs, is heat processed. I have seen pics (and a video somewhere) of workers melting lac in cloth bags by a fire and twisting the bag to extrude the shellac. While still hot the workers stretch the molten shellac into large sheets which are then cooled and broken up into flakes. Chemistry is not my strong suit but it would seem to me that heating the raw lac might change something about its compostion, possibly driving off volatiles or polymerizing the lac somewhat.
To close this long ramble I will post a quote from a book about finishing published in the 1920s as food for thought:
The Chemistry of Paints, Pigments and Varnishes by J. Gauld Bearn, copyright 1924:
"As a rule Button Lac is somewhat harder than ordinary orange shellac, owing to the small percentage of shellac wax that it contains"

Impressive, but not necessarily applicable since a clock is generally never in contact with human skin for any significant amount of time, or taken outdoors except when moving. Though I suppose in 275 years of moving, it probably has been done in the rain more than once, so perhaps it is resistant enough.

And certainly no finish will keep water out forever. I just don't want to have to keep a towel between my arm and the guitar, or panic and search for droplets every time it gets a little spritz of water on it.

I think it is safe to say that most knowledge of lac and shellac has been lost with the advent of cellulose and other modern coatings. The old timers who worked with this stuff are long gone.